Welcome back to Confessions of a Crypto Miner… my bi-weekly column about a crypto miner from 2013 trying to get caught up with the latest standards. I'm presently mining and reporting to you from a dual GTX 1080 based rig mining zCash.

In the last entry, I got my hardware & software set up and started mining. If you were monitoring the miner via the stats link, you may have noticed a few offline moments 2-3 days ago. This was due to me installing a nice new power monitoring setup and taking some measurements at different settings, all with the goal of finding the most efficient way to run the miner long term, to maximize profits. We now have all the data on hand and can now draw conclusions from it. There are two things I'd like to investigate with this article: 240 VAC's impact on power draw, and how the graphics card power limit setting affects profit margins.

Conventional wisdom with PSUs indicates that a higher line voltage will provide a higher efficiency. Thus, mining with 240 V AC power promises to be more efficient than using the American 120 volts. Conventional wisdom also states that this will probably be a small margin in the range of 2-3%. The 80PLUS standard indicates this, as well as Seasonic's own marketing material (I am using a Seasonic 650 W PRIME Ultra Titanium, for reference). Let's see the actual results, shall we?

Rounded, we have an average of ~1.0%, or honestly, nearly within the margin of error. It would seem these very high efficiency PSUs don't care much what line voltage they are fed. I have both 120 V and 240 V easily available in my house, so I will continue to run on 240 V. If you are considering getting a 220 V line installed, just to save a few percent on efficiency, make sure to do the math on installation cost and how long you will have to be running. For example, assuming profits of $5 per day, $500 to get 220 V installed, providing a 2% efficiency improvement, you'd have to be mining for 5000 days just to break even on the setup cost! However, the bigger your operation is, the more meaningful these small percentages will become, because installation cost is pretty much constant, while profits go up by 2% across your whole setup. Bottom line, always measure, do the math, and as I have said before "always have a plan." I suspect most users in North America to find the 120 V numbers to be more relevant to them, so I will short-term switch over to that for the next set of numbers, which are final earnings vs power limit setting on my two NVIDIA GTX 1080 cards.

The first chart shows mining efficiency over a range of GPU power limit settings. As expected, when you reduce the maximum power budget available to the GPUs you gain almost 40% in efficiency, due to the lower total cost for electricity. This would make you think that a lower power limit (such as 50%) should yield maximum profits. However, due to how profitable crypto mining presently is, that's not the case, at least for my setup. In fact, plugging my numbers into any online crypto earnings calculator for ZCash (assuming difficulty of 7684.6593, ZEC Price of 454.65 USD, kWh power cost $0.115) shows us that the "sweet spot" is in fact at either power limit 80% or 70%, both tying with a value of $5.59 per day. Very surprising how different that is from the illusion presented by the hashrate vs wattage graph, isn't it? Here again, collect your own data. For example Vega or Polaris have wildly different efficiency curves, so the sweet spot is most certainly different. Also interesting is that at some point, with high profits and low electricity cost, it just makes most sense to mine as many coins as quickly as possible, to get ahead of the difficulty curve. I may actually go this route considering I plan to hold some of my coins for speculation, especially considering the limited profit this whole ordeal actually yielded, which I will discuss now.

In conclusion, I should note that even after tuning for maximum efficiency, the difference in earnings over electric only came to $0.03 more per day moving from 100% to 70% power limit. Was that worth my time? Difficult to say, it took well over three hours to take all those readings and conclude this. In a year that will earn me only $10.95 more than had I just not cared. But it was kind of enjoyable for me… if you find that true, maybe tuning it is worth your time too. There are still things to investigate as well, such as the impact of underclocking and overclocking. Personally, I feel you should definitely pay attention to the risk of getting lost in the tuning side of the equation forever, without ever running a steady solid income.

A word on the PSU used, during all this 120 V vs 220 V discussion I forgot to bring up the small elephant in the room: Graphics card prices are not the only thing that got affected by the mining craze. I remember when an EVGA SuperNOVA 1300G2 could be had for ~$200 online and now it's either nowhere to be seen or goes for $400+. I bought my Seasonic 650 W Prime Ultra Titanium at $160. For context, the 650 W PRIME Platinum and Gold are currently priced at $130 and $100 respectively from Newegg in the present market. Let's say an average 80 PLUS Gold rated PSU is ~86% efficient at mining operating conditions, compared to ~92% and ~94% for the Platinum and Titanium units respectively, all other things being equal. So I would effectively be getting a 2-8% reduction in electricity consumption from the wall but at a $30-60 price hike per mining rig. At my current peak profit over electric of $5.59/day, this ideal situation of an 8% bonus over the gold PSU would have been ~$0.45/day which means it would have taken 134 days to break even and go to the territory where this more efficient PSU starts to finally pay for itself. In the long run, that 4.5 months may not seem bad. However, this is where other facts come into play, as they always do. Large operations, especially those with multiple machines could instead go for cheaper PSUs (e.g. 850 W Seasonic Ultra Gold at $120), and buy more GPUs with the money saved; GPUs which will churn through hashes from day one and generate income immediately. I can't really say with certainty a Titanium PSU makes sense large scale unless there is some evidence of a decrease in failure rate or other cost saving factors at play. Of course, we have no evidence for that to date and as such I can't say this "Titanium Premium" would be a good buy for a larger mining farm vs more GPUs, in my assessment.

67 Commentson Confessions of a Crypto Miner: Efficiency

silentbogo said:
Thermal stress on solder joints is a myth from GeForce 8-series era. It's not the solder balls that detach from PCB, it's a bonding array between the die and the substrate, and is not so much a thermal expansion problem, as a factory defect. It still happens on newer cards, but very-very rarely comparing to VRAM failures, which lots of people and even repair technicians confuse with GPU failure.

Ah I didn't know that. Any source? Shouldn't a factory defect per definition be present from the start?

W1zzard said:Ah I didn't know that. Any source? Shouldn't a factory defect per definition be present from the start?

It was a long time ago. The problem was an epoxy, or whatever type of the bonding material NV used in those cards, and forgot to account for thermal expansion, so during the normal operation the heat-resistant adhesive would hold the die in place and slowly but surely wiggle it out of the bonding spot, thus breaking the contact between die and substrate. Fixed since Fermi.

It looks to me that ATM it is worth going for the maximum hashrate and not worrying too much about electricity usage. (That is, given that electricity costs are not too high,temps are ok and the cards are not too inefficient going flat out.)

SirB said:Keep up the BS articles about mining. Watch your reputation as a tech site go down the toilet.
Absolutely pathetic...... Now watch me get banned. lol

I'm not mining myself but I find RTB's articles interesting. I like to keep up on new tech, even if I'm not planning on buying a pallet of GPUs tomorrow.
As far as I can see the content is factual and the tone as neutral as possible.

The mainstream press know next to nothing about crypto so it is nice to have some decent info here.
Crypto has become one of those subjects that everyone has an opinion on but hardly anyone knows much about.

IMHO anyone who has no interest whatsoever is free to not click on this article, and free to post in one of the other threads decrying mining.

OneMoar said:doubling the voltage doesn't really make that process any more efficient

Well, I mean PSU manufacturerers, the 80PLUS standards, and even these test results (albeit only at one percent) all disagree with you. SOMETHING inside the PSU becomes more efficient at higher voltage.

The surprising thing is that the doubling is not MORE efficient given the marketing they provide saying I should expect at least a 2% gain.

Beastie said:It looks to me that ATM it is worth going for the maximum hashrate and not worrying too much about electricity usage. (That is, given that electricity costs are not too high,temps are ok and the cards are not too inefficient going flat out.)

I'm not mining myself but I find RTB's articles interesting. I like to keep up on new tech, even if I'm not planning on buying a pallet of GPUs tomorrow.
As far as I can see the content is factual and the tone as neutral as possible.

The mainstream press know next to nothing about crypto so it is nice to have some decent info here.
Crypto has become one of those subjects that everyone has an opinion on but hardly anyone knows much about.

IMHO anyone who has no interest whatsoever is free to not click on this article, and free to post in one of the other threads decrying mining.

Thank you.

I see no reason why mining and non-mining articles can not coexist neutrally on a tech related website.

Honestly my opinion of crypto tech in it's current form is hardly positive (there is a reason the watt meter shot was chosen, anyone notice anything about the last 3 digits?), but I like to learn.

The higher the voltage the lower the Amps required to attain the same amount of Watts. There are many reasons why a higher voltage will give higher efficiency. But to be fair most of the gains are from supplying power over long distances. Most heat generated is from the amperage pumped through a wire and heat increases resistance of conductors (but not semi-conductors) and resistance lowers efficiency . Also voltage drop is less of an issue at a higher initial voltage which also helps to lower temps and lessen the required amps.

Because PSUs are made to handle both 120V and 240V supplies then they have to be made to handle the 120V amperage requirement which means a higher gauge wire is needed to pass code standards. This is another positive for 240V supplies since the wire used inside the PSU is much larger than needed which means it'll impeded 240V less and generate less heat as well.

SirB said:Keep up the BS articles about mining. Watch your reputation as a tech site go down the toilet.
Absolutely pathetic...... Now watch me get banned. lol

You think? Mining is very tech oriented. As it stands right now, it's not the way it was meant to be, but there is a lot of useful tech in there.

Fabio said:mining in pointless s*** that waste real resources

You know, every time I see a comment like this, it triggers me, just a little bit... I understand that mining caused a big GPU shortage. I'm a gamer too, hell, that's how I found this site originally way back in the day. But mining is making a lot of people money. People like me that struggle all the time financially, and people like daddy bigbucks who takes entire shipments of them. I was fortunate enough to get in while it was still reasonably possible to do so. The shortage had already begun, to an extent, but I was lucky enough to find a measly two cards for myself.

Personally I think mining is a little bit more important than gaming. I've been playing video games since I was at least as young as 2, but it's never earned me a single cent. Mining, however, has... and if it weren't for mining I would never have two GTX1070s. I'd still be happily chugging along with my old GTX660 Ti. Since then my mining has helped me out a lot, and things would be noticeably worse without it.

Been following the articles you put up @R-T-B , thank you for the interesting finds.

These sort of things pique my interest. Especially this one. Efficiency and power cost, because here in the Philippines we have a lot of gpu miners, I was wondering how they survive with their multi gpu rigs because electricity here isn't cheap, especially if you live in the city.

R-T-B said:It's not pointless per se, it is however debatable whether it is worth the energy cost. I'm unconvinced either way on that... but I do know one thing:

Efficiency is of the utmost importance.

hat said:You think? Mining is very tech oriented. As it stands right now, it's not the way it was meant to be, but there is a lot of useful tech in there.

You know, every time I see a comment like this, it triggers me, just a little bit... I understand that mining caused a big GPU shortage. I'm a gamer too, hell, that's how I found this site originally way back in the day. But mining is making a lot of people money. People like me that struggle all the time financially, and people like daddy bigbucks who takes entire shipments of them. I was fortunate enough to get in while it was still reasonably possible to do so. The shortage had already begun, to an extent, but I was lucky enough to find a measly two cards for myself.

Personally I think mining is a little bit more important than gaming. I've been playing video games since I was at least as young as 2, but it's never earned me a single cent. Mining, however, has... and if it weren't for mining I would never have two GTX1070s. I'd still be happily chugging along with my old GTX660 Ti. Since then my mining has helped me out a lot, and things would be noticeably worse without it.

you are only part of a speculative mechanis. mining produce nothing, you burn real resources to produce nothing, complicated algorithm that sometime are used to validate exchang of a fake money without guarantees( that are not a money cause no one would accept it as a payemen except some rarr cases) but it is only something worst than a mere speculative product, like a future or a commodity. I say worst cause it is a ponzi scheme, there is nothing under those cripto, and the day people stop trow in real money the castle crash down.
people are exalted of the cripto sayng they can free people from banks, but those currency failed on evrything, no equity cause all of those cripto are in the hands of few, and no one want it cause they are useless, the miners cache out for real money as fast as they can. mine as long as you can if you want, cause sooner or later such a wast of energy to feed a ponzi scheme-like game will be killed in some way

You can trash crypto all you want, but the facts are, at least for me, it's helped me greatly in my time mining. It's helped bail me out of touch financial situations and helped me get things I would otherwise not have been able to get. That's far from useless, fake, or producing nothing to me. Sure it could all be ruined someday, but the same is true for everything. Even the Sun will burn out someday. It's worth something because people say it's worth something. The same is true for the dollar. Even "real" currencies crash and are reduced to nothing. It's happened many times in our history. The Gold Standard is dead and gone, even the dollar is backed by nothing.

hat said:You can trash crypto all you want, but the facts are, at least for me, it's helped me greatly in my time mining. It's helped bail me out of touch financial situations and helped me get things I would otherwise not have been able to get. That's far from useless, fake, or producing nothing to me. Sure it could all be ruined someday, but the same is true for everything. Even the Sun will burn out someday. It's worth something because people say it's worth something. The same is true for the dollar. Even "real" currencies crash and are reduced to nothing. It's happened many times in our history. The Gold Standard is dead and gone, even the dollar is backed by nothing.

This is what keeps me from outright trashing it, really. Stories like this.

hat said:
Personally I think mining is a little bit more important than gaming. I've been playing video games since I was at least as young as 2, but it's never earned me a single cent. Mining, however, has... and if it weren't for mining I would never have two GTX1070s. I'd still be happily chugging along with my old GTX660 Ti. Since then my mining has helped me out a lot, and things would be noticeably worse without it.

Same for me, I'd never have been able to justify buying anything above a 1060. Most of the cards I have now, I can justify buying them as when I mine on them, they pay for themselves. Most of the cards I have are upgrades I've paid for from mining on the previous cards.

silkstone said:Same for me, I'd never have been able to justify buying anything above a 1060. Most of the cards I have now, I can justify buying them as when I mine on them, they pay for themselves. Most of the cards I have are upgrades I've paid for from mining on the previous cards.

i have a machine sat outside in my caravan.. along with my desktop gaming rig it is producing "money".. no effort on my part is required.. i am seeing around $1000 per month at the moment a couple of weeks back when eth was higher i was seeing up to $1500 dollars per month.. my caravan is kept nice and warm.. no worries about frost damage and its helping heat my house..

if the same thing happens this year as last year and i hold the mined proceeds.. i could be looking at $50000 dollars or so.. from my modest mining efforts..

if things keep going as they are.. lets say i am skint and need the ready cash.. its hard to believe that the $1000 or so a month wont come in handy..

this does require a cash investment.. nothing comes totally free.. and it is all dependent on what happens to crypto prices over the coming year.. last year some of them went up by a %1000 or so..

the naysayers will shout out "that aint gonna happen".. well for sure it aint gonna happen for them.. but it just might happen for me.. :)

does money grow on trees... dunno but it might.. he he..

i did lose 1/3 of a bitcoin current price about 4k.. that was my first three months mining and holding bitcoin.. i was a bit lapse about leaving it sat in the nicehash wallet.. a mistake i wont make again..

i mine but i am really a hodler.. which means i hoard what i have as opposed to cashing it out and spending it..

trog

ps.. there is a possibility i might get my 4K back.. nicehash say they are gonna do this.. they are gonna say when and how at the end of this month which is getting close..

OneMoar said:yes but how many folks here other then RTB have done the power-usage to profit calculation in detail

I have , i quite literally pay separately for its power, and that makes budgeting quite easy ,it inspired me to move my own 8 580s from two rigs into one, plus ive spent hours fine tuning so far for efficiency, im at about 1300 watts max but fluctuations down to 900 on two psus ,jic, i definitely saved 150-300 watts with the swap and its easier to tune , looks a mess mind ill post a pic once I have slept, just got it running right now.